From New England to the upper Midwest, four states are hosting primaries Tuesday.

The most interesting contests are in Wisconsin and Minnesota, which both hold primaries for Senate and for several competitive House seats. And in two safe Democratic districts — one in Minnesota and one in Connecticut — primaries will likely pick new members of Congress.

Minnesota Republican Stewart Mills, a wealthy businessman who lost two consecutive races to Democratic Farmer Labor Rep. Rick Nolan, announced Wednesday night he is unlikely to run for the 8th District in 2018.

But he’s leaving the door open to future political activity, and potentially another congressional bid in 2020 — “if there is a meaningful change of leadership and priorities” at the National Republican Congressional Committee.

For months, Minnesota Rep. Rick Nolan has been dancing with a run for governor. Friday afternoon, he announced he wouldn’t seek the state’s top job after all, suggesting he’ll run for re-election in the competitive 8th District in 2018.

“The challenges and consequences of the issues facing our Nation in Washington are too important for me to walk away from at this time,” Nolan wrote on Facebook Friday afternoon.

Rep. Rick Nolan, seen here with his wife Mary in Brainerd, Minnesota, last year, says he’s now closer to a 2018 run for governor in the North Star State. (Tom Williams/CQ Roll Call File Photo)

As he heads out of Washington for two weeks back home in Minnesota, Democratic-Farmer-Labor Rep. Rick Nolan has a big decision to make that could have implications for his party’s efforts to retake the House majority in 2018.

The Democratic Congressional Campaign Committee on Monday is naming 19 members to the Frontline Program for its most vulnerable incumbents in 2018.

The initial Frontline roster, obtained first by Roll Call, is about half freshman members. Eight members won in districts President Donald Trump carried last fall. And all of them, save for one, are National Republican Congressional Committee initial targets.